There is a method for manufacturing a cylinder of quartz glass by drawing out a circumferential edge of an end of a columnar quartz glass rod while rotating the rod relatively to a piercing member in the condition that the end of the rod is heated and softened while the rod is rotated about its longitudinal axis, and a sharp edge of the piercing member is engaged with a central portion of a surface of the end of the rod (Japanese Patent No. 2798465). According to this method, as shown in FIG. 12, a glass rod 100 made of quartz is prepared. A dummy cylinder 123 is welded to an exit side end surface of the glass rod 100. In the condition that a piercing plug 131 is applied to a central portion of the end surface of the glass rod 100 while the glass rod 100 supported by the dummy cylinder is rotated, part of the glass rod 100 around an end of the piercing plug 131 is heated and softened by heating means 140. The piercing plug 131 is fixed to a support rod 132. The support rod 132 is fixed to a fixing portion 135 so that the support rod 132 can rotate about its axis along with the piercing plug 131. A left end of the glass rod 100 is held by a chuck 112 of a first feed table 111. The other end of the glass rod 100 is held by a chuck 122 of a second feed table 121 through the dummy cylinder 123. The first and second feed tables 111 and 121 are mounted on an entrance side base 110 and an exit side base 120 respectively so that the first and second feed tables 111 and 121 can move on the bases respectively.
The heating means 140 is configured to have a cylindrical heating element 103a that covers the neighborhood of an abutment portion where the glass rod 100 and the piercing plug 131 abut on each other, and a coil 103b having an appropriate number of turns and disposed around the outer circumference of the heating element 103a. Heat induced by a high frequency current passed through the coil 103b raises the temperature of the heating element 103a to a value equal to or higher than the softening point of the glass rod 100 to thereby heat part of the glass rod 100 in the neighborhood of the abutment portion of the piercing plug 131.